A fairly large, pale grayish brown Psathyrella-like mushroom of swampy ground and decayed aspen wood in western North America, often near beaver ponds. It was described in 1972 as Psathyrella uliginicola and moved to Coprinopsis in 2015 on DNA evidence, although it does not dissolve into ink like typical inky caps. It is rarely reported.
Solitary in swampy areas under brush or on decayed aspen wood, especially around beaver ponds.
Distribution
Western United States: described from Pole Mountain near Laramie, Wyoming, with collections from Idaho, New Mexico and Utah; also illustrated from California on the California Fungi site.
Characteristics
Cap: 5-10 cm, globose becoming hemispheric to broadly convex or nearly flat; pallid to grayish, wood brown when moist, somewhat hygrophanous, faintly silky; margin becoming grooved with age. Gills: narrowly attached, crowded, thin, pallid becoming dark vinaceous brown, edges white and finely scalloped. Stem: 8-12 cm long, 12-15 mm thick, equal, hollow, rigid and brittle, white and silky, becoming lengthwise grooved; lower part discoloring when handled; white mycelium at base. Veil: thin partial veil leaving fibrils on the stem and a fringe on the cap margin. Spores: 10-12 (-15) x 5-6 um, elliptic to oblong, bean-shaped in side view, smooth, with an inconspicuous pore (Smith 1972 protologue).
